Water cooler



FIG. 1 is a top, front, side perspective view of a water cooler showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a rear view thereof.

The broken lines in the drawings are included for the purpose of illustration and form no part of the claimed design. 

CLAIM The ornamental design for a water cooler, as shown and described. 